부당이득법에 있어 형식적 의사의 자유에서 실질적 정당성의 파악으로의 발전 필요성 -대상판결: 대법원 2022. 11. 30. 선고 2020다224685 판결-

This ruling held that the appeal court should have reviewed whether the state had allowed the buyers and their successors to use the state-owned land for free, which had not been purchased or hired by them, and that it should have decided whether they had to give back their enrichment to the state or not. The unjust enrichment liability from this standpoint is decided by the fact whether one intended to do something for the other to enjoy the value increased by the former. This approach is derived from the Savigny's theory. The origin of unjust enrichment doctrine can be traced to condictio in Roman law that was aimed to recover economic value, not the freedom of choice, and not necessarily linked to the invalidity or cancellation of a contract. In the first half of the 19th century, Savigny reinterpreted condictio as an actio based on the principle of formal freedom of choice, which was the zeitgeist of his time, and condictio began to be seen as the remedy for the invalidity or cancellation of contracts. Since then, it has become common to assess the absence of legal basis by examining the lack of genuine intention to give benefit. However, there has been a huge change in economic and social area from the 19th century to today. The lassez-faire principle was abandoned long ago, and now the practical fairness of transactions is stressed. This country has also remained committed to the strong egalitarian ideals, since its first constitutional law was founded, and the discourses of fairness have increased in relation to a range of social issues since 1997 IMF crisis. The unjust enrichment law needs to move its basis from the formal freedom of choice to the practical fairness of transactions. Besides the absence of intention approach only focused the claimant's side as a justifying ground of unjust enrichment liability. It is equally necessary to see into the debtor, that is, the recipient's side as is done in other causes of liability such as of delicts. The practical fairness of transactions cannot be reviewed without considering the economic value of the contracted object, and the economic value is transferred by the just compensation. This value differs from the rights transferred by the contract and law. The justness of the compensation can be assessed through the reciprocal compensation and the approval supported by the non-prescriptive standards. From this perspective, the issue in this case is not whether the state intended 57 years ago to permit the free use, but whether it is just for the state to now demand a fee unclaimed for several decades from the owners of 57-year-old dilapidated 40-squaremeter flats. This essay argues the latter approach is more reasonable today.